1. Field of the invention
This invention relates to a protective cover of a terminal for connecting posts on a plurality of stationary batteries, and relates to a protective cover of a connecting terminal wound onto a battery post. More particularly, it relates to a protective cover of a battery post connecting terminal that can be held as it is opened at a desired regulated angle.
2. Related Art
One of the problems with the development of commercial electric cars is the insufficiency of the electric capacity of stationary batteries. To deal with this problem, it is necessary to increase the electric capacity of stationary batteries by connecting their posts either in series or parallel. To interconnect battery posts, a plurality of batteries are placed side by side and electrically conductive connecting terminals are fixed to the respective posts to be connected.
FIGS. 8 (A) and (B) shows how battery posts are to be connected; FIG. 8 (A) is a perspective view of the individual components yet to be assembled; and FIG. 8 (B) is a perspective view of the components as they as fixed to each other. A plurality of batteries 10 are placed side by side so that their battery posts 14 are adjacent to each other. A connecting terminal 8 is fixed to the battery posts 14, thereby establishing electrical connection between the two batteries 10. If the battery posts 14 are bolts, the connecting terminal 8 can be readily fixed to the posts by means of nuts 42 which are threadable over the bolts.
If the connected battery posts 14 are bare, they may be damaged upon contact with external objects and the damaged battery posts may deform too severely to prevent subsequent removal of the connecting terminal 8. Conversely, the distal ends of the battery posts 14 may damage other battery members such as wire harnesses.
Another problem with the bare state of electrically conductive portions such as battery posts 14 is that shorts may potentially occur upon contact with other conductive members.
To prevent direct exposure of the battery posts 14, they have to be protected with a cover. Various cover designs are known that are intended to protect single battery posts 14; however, cover designs capable of protecting a plurality of battery posts are available only at unsatisfactory levels principally because they often require complicated procedures for detachment. Under the circumstances, it is desired to develop post covers that can be easily mounted during the connection of battery posts 14.
Terminals connected to battery posts on the positive electrode side are provided with protective covers to prevent shorting with the vehicle's body. To insure high operational efficiency in connecting the terminals to the battery posts, the protective covers are so designed that they are free to open or close, as proposed in Unexamined Published Japanese Utility Model Application Sho 58-11864 or the like.
FIG. 15 shows a conventional battery post connecting terminal; the connecting terminal 121 comprises an electrical contact portion 123 that is wrapped onto a battery post 120 and an electric wire connecting portion 125 for connecting an electric wire, and a protective cover 141 is so adapted that when it is mounted on the connecting terminal 121, it is capable of covering the entire part of the latter including the battery post 120. The protective cover 141 is made of a thermoplastic resin such as polypropylene or polyamide and comprises a cover portion 142 that encloses the electric wire connecting portion 125 and a lid portion 144 that serves as a lid over the electrical contact portion 123 via a hinge 143.
Before the connecting terminal 121 is wrapped onto the battery post 120, the protective cover 141 is mounted around the wire connecting portion 125 by means of the cover portion 142. The wrapping portion 126 of the terminal 121 is then slipped over the battery post 120 projecting from the top of the battery and by tightening a bolt 128 inserted through clamping lugs 127 formed at the distal end of the terminal 121, the latter is positively secured to the battery post 120.
The lid portion 144 of the protective cover 141 then pivots about the hinge 143 bordering on the cover portion 142, whereby not only the terminal 121 but also the bare portion of the electric wire 124 near the wire connecting portion 125 can be covered completely.
This offers the advantage that when installing or replacing batteries on a vehicle, the lid portion 144 can be freely put on the electrical contact portion 123 with the protective cover 141 being mounted on the connecting terminal 121; furthermore, the bolt 128 can be easily tightened or removed during maintenance, thereby assuring ease in connecting operations.
The conventional protective cover 141 however has had several problems. First, it is a one-piece molded part in which the cover portion 142 and the lid portion 144 are connected via the thin-walled hinge 143 to permit the cover to be freely opened or closed. Since it is difficult to insure satisfactory strength for the hinge 143, the latter may potentially break if an external force F is applied from above onto the protective cover in an open state. This possibility is particularly great when the hinge experiences deterioration over time as a result of repeated battery changes and the like.
Secondly, the freely openable protective cover 141, although it permits the electrical contact portion 123 to become exposed readily, has to be held open with clearance angle .theta. being wide enough to provide a free space for efficient performance of the operation to tighten or remove the bolt 128. In practice, however, this has required for the operator to assure the operating space by holding the protective cover 141 with one hand while performing the necessary work such as tightening the bolt with the other hand. As a result, it has been impossible to maintain a constant clearance angle .theta. for the protective cover 141 while it is open and, eventually, the cover has lowered the efficiency of tightening or loosening operations by serving as an obstacle.